Attachment for oscillation generators



Dec. s, 1925. 1,565,092

4 H. C. HARRISON ATTACHMENT FOR OSCILLATION GENERATORS Filed June 23, 1921 3 Sheets-Sheet 1 Z3 44 1 l I ."f I (5.

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Dec. 8, 1925- i l 1565.09

H. C. HARRISON ATTACHMENT FOR OSCILLATION (rENERATORSA Filed June 25. 1921 3 Sheets-Sheet Dec. 8 1925 H. C. HARRISON ATTACHMENT FOR OSCILLATION GENERATORS Filed June 23, 1921 3 Sheets-Sheet 5 I v5 6 40 40d y;` 40e 4401" f5( 6 f6 f6 I f 5f ff Q2) 54 0 e J4 J4 ff ff a 2.3 e

23a Z3 f4( 2,34/ 23e Patented Dec. 8, 1925.

UNITED STATES PATENT oFFlcE.

HENRY C. HARRISON, OF PORT WASHINGTON, NEW YORK, ASSIGNOR TO WESTERN -:ELECTRIC COMPANY, INCORPORATED, 0F NEW YORK, N. Y., A CORPORATION OF NEW YORK.

ATTACHMENT ron oscrLr-.ATIoN GENEaAToRs.-

Application filed June 23, 1921. Serial No. 479,798.

To all 'whom it may concern.'

Be it known that I, HENRY O. HARRISON, a citizen ofl the United States, residing at Port IVashington, in the county of Nassau, State of New York, have invented cer-tain new and useful Improvements in an Attachment for Oscillation Generators, of

which the following is a full, clear, concise,.

and exact description.

This invention relates to oscillation generators of the type having an adjustable oscillatory circuit.

The primary object of this invention is to provide acircuit setting and a frequency indicating attachment for an oscillation generator. i

Another object is to supply a simple des vice which will elfect 4the desired adjustments with accuracy and'd-espatch.

Still another object is to provide a controller' for adjusting and indicating the frequency and simultaneously suppressing the harmonics of the current supplied by the oscillator.

Oscillation generators adapted to produce alternating currents of dierent frequencies extending Vover a wide'range are well known. In order to generate currents of widely different frequencies with. ar single circuit arrangement, it is necessary to provide means whereby the natural period of the oscillatory circuit may be varied between wide limits. Moreover, to supply a wave of fundamental frequency 'only to the load circuit, a wave lter adapted to lsuppress harmonics of the 4fundamental frequency, normallyproduced by an oscillator of this type, isin general connected between its output circuit and the load circuit to which the current is supplied. Y

One arrangement for this purpose comprises an electric discharge device having acathode, an anode and a grid, an inductance having a subdivided portion,` a subdivided condenser, a continuously Variable condenser and a series of switchesV and.l controllers associated therewith, and` inductances and capacities together with a series of control switches therefor. One group of @switches and the controllers are separately operated to regulate the amount of the inductance, the number of subdivisions of the main condenser and, if desired, the portion of the auxiliary condenser included in the oscillatory circuit to determine its natural period. The second group of switches, also separately operated, are adapt-ed to control the values of the inductance and capacities of the second group connected between the output terminals of the oscillator and the load circuit, to lconstitute a wave filter adapted topass a definite band of frequencies which includes that determined by the setting of the oscillatory circuit.

The oscillator referred to above is in one instance designed to supply currents of frequencies varying from 200 to 3000 cycles, and in order to provide oscillatory circuits having natural perio ls variable between corresponding limlts, siX inductancelsubdivisions and ten main condenser subdivisions are employed, in association with the continuously variable condenser. Moreover, variations of the filter constants are effected in vsix steps. Hence there are six switches in each group. Each switch has three positions which may be designated up, neutral and-down and the switches are arranged in pairs which are simultaneously operated. Since the main condenser is varied in ten steps its controller will be provided with ten contacts.

By actuating the switches and controllers in proper sequence, the frequency of the current supplied to the load circuit may be varied from the minimum to the maximum limit for which the oscillator is designed.

To illustrate the sequence of operation of the switches and controllers the yfollowing' description of the order in which they are actuated to effect variation of the constants pear in the drawings.'

To supply a current of 200 cycles to the load circuit, switches 1 will be up, the other five down, and the main and auxiliary condenser controllers will bein of position. To effect variation of-thefrequency between 200 and 300 cycle`s,v the auxiliary condenser controller will be actuated throughout its complete, range, the con-` ary condenser control er will be /mcved over" its complete range, the main condenser controller will then be moved to position 3,

lthe auxiliary controller over its complete range, and so on; until the frequency of 300 cycles is reached.

At this position keys 1 will be moved to neutral keys 2 will be moved to the up position, and the other keys will remain ,down. The main and auxiliary condenser controllers will then be alternately operated, as'described above, and the frequency of the current supply will thus be varied between I 300 and L150 cycles.. or a frequency range between 450 and 700 cycles, keys 2 will be returned to neutral, keys 3 will be moved to the up position, the other keys will remain in down position, and the main and auxiliary condenser control- 1ers will be operated in the order described above'for the first frequency range.

For succeeding frequency ranges, that is, 700 to 1000, 1000 to 1500, and i500 t0 3000,

fthe position of the switches 3, 4, 5, and 6 will be .changed successively as just described for switches 1 and 2, and after the actuation of each switch the condenser controllers will be operated in the order described above until in the final position the keys 6 lare up, the others are neutrah and the condenser controllers occupy their final positions. a

In this mannerdi'erent combinations of Q inductances and capacities are provided both for the oscillatory circuits and the filters. Of course in the initial position of the switches and controllers, that is, for a frequency of 200 cycles, a fixed amount of capacity is associated with a fixed value of mductance in the oscillatory and filter cir- By properly subdividing the inductance, using equal subdivisions of the main capacity, and giving the auxiliary -condenser a capacity. value equal to one subdivisionof the main condenser, a generator adapted to supply currents of frequencies which B,may be continuously varied over the complete range for which it is designed may be obtained. v

The present method of frequency setting which requires the manual operation ofthe different switches andcontrollers is both slow and awkward, isa tax upon the operator, and depends for its accuracy upon the proper selection and setting of the switches and controllers. These disadvantages are particularly noticed whenevem attempt islmade lto swing the frequencyck and forth over a range4 of values as is required, for

example, when attempting to determine the resonance point during impedance analysis measurements. Moreover, since the change of frequency produced by a slight movement of the auxiliary condenser controller produces a relatively small chan e in the frequency supplied to the load circuit, the degree of accuracy of the setting will depend upon the ability of the operator to effect the proper adjustment, and if absolute accuracy is required this will involve checking and readjusting the setting. The attachment to be hereinafter described is adapted to overcome these difficulties and expedite the frequency setting of an oscillation generator.

In accordance with this invention a devvice has been provided comprising a single ler, and to an intermittent gear adapted/ drive a cam 'shaft carrying a plurality of cams. Each cam is associated with a spring controlled lever connected to a pair of keys or switches. The lever is also connected to an arm mounted on a rod secured to the auxiliary condenser and about which it is adapted to be bodily rotated. Hence by rotating the handle ineither direction the contact arm of the main condenser controller nd the cam shaft will be rotated. The ormer to stepwise control the number of subdivisions of the main condenser included in the` oscillatory circuit and the latter, through its cams and associated levers, will operate the switches to control the value of the inductance included in the oscillatory circuit, and also the value of the inductance andA capacity included in the filter circuit associated with'the output terminals of the oscillator. Movement of the lever and hence the arm about its pivotal point'xwill effect the adjustment of the auxiliary condenser.

One design of device for-effecting this result is shown by way of example, in the attached drawings, in which Fig.'.1 is a side -view of the attachment; Fig. 241sv a plan view thereof; Fig. 3 is' section on .line 3 3 of Fig. 1 showing the gear mechanism;'Fig. 4

is section online 4-4 of Fig. 3; Fig. 5 is a section of line 5-5 of Fig. 3; Fig. '6 shows the relative positions of the cams for one setting of the oscillatory and filter cir-- cuits; Fig. 7 shows a portion of the chart .with which the index pointer cooperates; and Fig. 8 illustrates schematically an oscillator with which this attachment may be employed. e

Referring toFigs. 1 and 2. 1 indicates a switchboard, which may be the face plate of an nclosing casing for the various parts of 'Ill Bit

the oscillator, upon'which the various circuit wires, sockets for the electric dischargcdevices, and control switches or keys 2 and 2 are mounted. At the bas-c and in front of this board is a housing 3 forthe condensersten semi-circles corresponds to one in uctance and filter setting of the circuits associated with the vacuuml tube device.

Control lever 8 having a screw threaded portion 9 is provided with a handle 10 whereby the lever may be rotated and bodily moved in a horizontal plane. The arm 12, having one end mounted on the 'pivot 11 is secured to the lever 8 so that these two elements move in unison when the lever' is bodily rotated about the pivotal point 11. Mounted upon the screw threaded portion of the lever 8 is a nut 13 provided with depending portions 14 engaging the arm 12 and carrying the index pointer 15. By this arrangement the nut is prevented Jfrom rotating with the handle 10, but is 'free to move longitudinally on the lever 8 and thereby carry the pointer 15 to indicate the semi-circular line desired.

The movable plates of auxiliary condenser 4 are carried by the pivot 11 to which the arm 12 is also secured, so that upon the rotation of the lever 8 about this pivotal point the movable plates of the auxiliary condenser will be adjusted relatively to the fixed plates associated with them.

The lever 8 is connected by a universal joint 16 to a 4sleeve 17 having a rectangular -bore into which projects a small rod or shaft 18 connected by a universal joint 19 to a gear shaft 20. This coupling connection is designed to permit the lever 8 to be rotated by the handle 10 in all positions of the. lever. The sliding connection between the sleeve 17 and rod 18 acts as a compensator to permit longitudinall movement of the lever 8 relatively to the gear shaft 20. necessitated by the fact that the. pivotal pointl 11 about which it may be bodily rotated in a horizontal plane does not coincide with the inner end of the lever 8.

The gear shaft 2O projects through a bearing 21 into the gear casing 6, andvis provided at its inner end, as shown in Figs. 3 and 4, with a beveled gear 22. A plurality of levers 23, sixv in number, extend from the other side of the casing 6 and are secured to a series of rods 24 each of which is connected to a pair of switches or keys 2-and 2.

As shown in Figs. 3, 4 and 5, the beveled gear 22 meshes with a beveled gear 25 which' drives a gear train consisting of the ears 26, 27, 128 and 29, to the latter of whleh a disc 30 is secured. The ear wheel 29 is mounted uponl andsecure to the shaft 31,'y

carrying an arm 32 adapted to engage a series-of contacts 33 mounted upon the eriterior of the casing 34, which serves to enclose the condenser 5. The contacts 33 are connected to subdivisions of the condenser 5, and hence, as the gear 29 is rotated, contact arm carried thereby will at different points in its rotary motion engage these contacts.

The gear casing 6 is provided with a detachable cover and a bracket detachably secured to the bottom thereof. The bearings 'for the drive gear shafts are provided in this bracket and in the bottom of the casing.

The disc 30 is provided with a depressed portion 35 within which is mounted a lug 3G ada ted to engage one of the projecting arms 3 of the intermittent gear wheel 38.

. 'lhe gear wheel 38 is 'secured to a cam shalt 39 provided with a plurality of cams 40, each of which is adapted to engage one of the levers 23. A plurality of springs 41 are connected at one end to the bar 42 secured to the casing near its top, and each spring has its opposite end connected to one of the levers 23 so that the levers normally, tend to occupy elevated positions.

The cams 40 are designed to determine a plurality of different positions for each of the levers 23"L to 23t inclusive, as Yshown in Fig. 5, which will be designated up, neutral and down, and they are secured to the shaft to control the levers and hence the switches in a definite'cycle. i

, Reerring now to Fig. 6, the cams are differentiated by the sutiixes a, b, c

I 7 d, e,.and mi, and correspond with the` similarlyidentied levers shown in Figure 3, hence cam 40a controls lever 23, cam 40b cooperates with lever 23h, and so'on.

As shown in Fig. 6, cams 40a and 4()t are provided with surfaces of two. different radii, whereas the other four cams 4()b to 40 inclusive have surfaces of three dii'erent radii. The cam 40 has surfaces of the shortest and intermediate radii, and cam 40f has surfaces of the intermediate and longest radii. Consequently the levers 23a and 23t which these cams respectively control will have but two positions, that is, lever 23", and hence the switches 2 and 2 connected thereto by the associated rod 24, can occupy neutral and upf positions only, and the lever 23, and therefore the switches 2 and 2 connected thereto by the corresponding rod 24, can be set only in the neutral and down positions.

Fig. 7 shows a broken section of the chart 7 fran oscillator adapted to produce a range of frequencies from 200 to 3145 cycles. This range is used merely for the purpose of illustrating one particular range 'of freuency which ,a single oscillator may prouce, but it is to be lhiderstood that by a proper selection of the -iqnuctance and iso capacity values for the oscillatory circuit of 200 to 315 cycles, a second set 315 to 500 f put and output circuits, and

cycles and so on, while the last band indicates frequencies of 1985 to 3145 cycles. Each semi-circular line will `be provided with scale marks 44 to identify the cyclave of the current generated and their number will depend upon the calibration desired. The scale may indicate unitary differences 1n the frequency of the current `generated, but, as a matter of fact, subdivisions of| five cycles will probably be found satisfactory for practical purposes.

For a complete frequency range whlch 1s subdivided as given above, an oscillator pro-l vided with a single set of inductances of 2.1, .85, .336, .136, .0534 and .0214 henries respectively, a single range of capacity values of .12 to .3 microfarads for the main condenser and a continuously variable condenser of .018 microfarads, Will be used.

Fig. 8 is a diagrammatic representation of one type of vacuum tube oscillator with which the attachment herein described may be used; The three element electric discharge device 45 having a cathode, a control element and an anode, has inductances 46 and 47 respectively connected in its ina pluralityI of taps 48 are associated with the inductances. The ca acity 49 is connected to the leads-50 with w ich the taps 48 are designed to be selectively connected by Athe closure of the first of the switches 2, shown in Fig. 1. A pair of adjustable condensers 4 and 5 are shown as adapted to be connected in parallel with the condenser 49 and the inductances 46 and 47 to constitute the oscillatory circuit. Extending from the oscillatory circuit are a pair of conductors 51. Any one ofl a plurality of filters, di'agrammatically shown at '52, may be selected and simultaneously connected to the conductors v51 circuit 53 by the switchesf2, shown in Fig. 1.

Upon" the rotation of the'lever 8 and under the control of the arm 32, different portions of the condenser 5 will be successively associated in shunt with the condenser 49 to vary the periodicity of the oscillatory circuit. By bodily rotating the lever 8 about the pivotal point 11, any desired portion of the condenser 4 may also be connected in parallel with the condenser 49 or condenser 49 and a desired subdivision or subdivisions of thecondens/er 5.

ach filter is designed quencies below the upper to pass only fre-- and the load A limit of the range indicated bya single group of lineson the chart 7, that is, the lower filter will onlyv pass currents of frequencies up to 315 cycles,

the next filter will have a cut-off limit of 500 cycles and so on. While these filters are diagrammatically shown as separate` elements this is done merely for convenience of illustration. The arrangement preferred is one in which the first key 2 will connect a filter for the first frequency range between the oscillator and theqload circuit, and the other keys 2 will control the connection of additional inductances and capacities to constitute therewith a filter for the band of frequencies within which the setting falls.

The operati-on of the controller, and the relation of the various lements for a particular frequency setting will nov7 be described. For purposes of illustration it will be assumed that the pointer 15 stands opposite point 2,05 on the first line of the first group of the chart 7, and it is desired to supply a frequency of 589cycles toga load circuit. the first mark 44 on line four of the third group. Under the conditions assumed, the first keys 2 and 2 will be in the up position, and the other five down7 and hence the lever 23a will be in engagement with the short radial portion 54 of the cam 40, and the other five will be depressed by their engagement with the longest radial portions 56 of the cams 40", 40, 40",`40 and 40'. Also the inductances 46 and 47 will be connected in the input and output circuits of the tube 45. A portion of the auxiliary condenser 4 will be connected in parallel with the condenser 49, and the contact arm 32 will be in neutral position, that is, the condenser 5 Will be cut out.

VTo effect the desired adjustment, the lever S is rotated by the handle 10. The nut 13 will be moved longitudinally of the lever by the screw 9 until the pointer 15 carried by the nut will be opposite or coincide with line four of the thlrd group. Simultaneously the drive train will rotate the Contact arm 32 connected to gear 29 by the shaft 31 to successively engage 4the series of contacts 33 connected to the subdividedcondenser 5 and will move the cam shaft 39 one step for each revolution of the gear 29. Engagement of each of the condenser contacts occurs at the moment the pointer 15 is opposite each of the lines in the first and second groups as well as at the instant it coincides with the first, second, third and fourth lines of the third group. At a definite point in the revolution of the disc .30 secured to the gear 29, the lug 36 mounted thereon will engage one arm 37 of the intermittent gear 38 and move it a step, thereby rotating the cam shaft one sixth of a revolution. The end of the arm 37 will project into the recess 35, whichv should be' of such dimensiops that the arm engaged-by the lug will ymove freely into wheel engage the adjacent face of the and out of this'recess without binding. The engagement of the lug with the arm occurs when the pointer 15 is passing from the last line of one group tothe first line of the`\ next. During the remainder of the revolution of the gear 29, the adjacent arms 37 of the .in isc 30 and thereby retain the cam shaft in the adjusted position.

As the pointer 15 traverses the space between the last line of the first group and the first line of the second group on the chart 7, the intermediate face 55 of cam 40 engages the lever .23a thereby returning the first pair of keys to neutral position. At thesame time the lever 23 is drawn into engagement with the face 54 of cam 40b by its controlled spring 41 and the second pair of keys are thereby moved to the up position. During the time the pointer moves from the last line ofgroup 2 to the first line of group 3, the face 55 of cam 40b comes into engagement with the lever 23b and forces it into neutral position against the action of its spring 41. Simultaneously therewith the face 54 of the cam 40G being opposite the lever 23, its associated spring 41 moves it into up position.` Further rotation of the handle to move the pointer opposite the fourth line of this group rotates the arm 32 of the main condenser controller into engagement with the third contact of the series 33. The arm 8 is then rotated about the pivotal point 1l to a point opposite thefirst indicating mark 44. With this setting of the switches and controllers, two sections of both inductances 46 and 47 are short-circuited, three subdivisions of the main condenser and a portion of the auxiliary condenser are connected in parallel with the condenser 49, and a filter, adapted to pass the band of frequencies within which the desired frequency occurs, namely 500 to 795 cycles, is connected between the oscillator and the load circuit.

In similar manner any other frequency setting may be effected. If now it is desired to set the oscillator to supply a frequency of 2684 cycles, we will proceed as above to set the pointer l5 opposite the intersection of the third radial mark 44 with the seventh semi-circular line of the sixth group on the chart 7. In this case the levers 23, 239, 23, 23d, and 23e/would engage the intermediate faces 55 of their corresponding cams and the lever 23f would engage the face 54 of the cam 40f, and hence the first five switches 2 and 2 would be in neutral position and the sixth pair of keys would be up From the preceding description it will be evident that this attachment is designed to effect grouping of proper values of inductances and capacities to constitute oscillatory' circuits and wave lters ada e to be associated with an electric dischar device and to indicate the frequency of the current su plied by the oscillator to a load circult.

AHence the type of oscillator, that is, whether the oscillatory circuit is connected as herein shown or in either the input or output circuit is a matter of choice. In other words, the invention may be used with any design of oscillator which is adapted to have the frequency of the current supplied thereby determined by the constants of a tuned circuit associated with a source of current.

The present invention has been de'scribed in connection with an oscillation generator, but obviously7 in certain of its aspects it may be used for other purposes.

While certain specific details have been shown and described with the object of completely and clearly disclosing the nature of the invention, it is to be understood that this invention is not limited thereto, but only by the scope of the attached claims.

What is claimed is:

1. The combination with an oscillation generator including an electric discharge device and an oscillatory circuit of means for adjusting the constants of said circuit /icluding a plurality of switches and controllers, and means to actuate said switches and controllers in a definite sequence.

2. The combination with an oscillation' v cuit for transmitting current from the enerator to the load circuit, means to a just the constants of said lter, and means for simultaneously actuating all of said means.

4. The combination with an oscillation generator comprising an .electric discharge device and an oscillatory circuit of means to adjust the constants of the circuit, means to indicate the frequency of the current supplied by the generator, a load circuit, a filter connecting said generator to said load circuit for transmitting current from the gen-v erator to the load circuit, means to adjustl the constants of said filter, andl common means for actuating all of said means.

5. The combination with an oscillation generator comprising a source of current and an oscillatory circuit of a plurality of switches and controllers for adjusting the constants of said circuit, a lter associated Withjsaid generator including means to adjust the constants of said ilter, and means I to control said switches, controllers and filter adjustin means. l

6. The com ination with an oscillation generator ycomprising a source of current and an oscillatory circuit of a plurality of switches and controllers for adjust-ing the constants of said circuit, a filter associated with said generator including means to adl 'ust the constants 'of said filter, a frequency indicator for the generator, and means to control said switches, controllers, adjusting means and indicator.

7 An oscillation generator comprising an electric discha'rge device, an oscillatory circuit, means for continuously varyin the natural period of said oscillatory circuit, means for indicating the frequency ofthe current vsupplied by the generator, and means for controlling the operation of the varying means and indicator.

8. An oscillation generator attachment comprising a control lever adapted to be given two modesotmovement, a plurality of switches, a plurality of rotary controllers,

means operated by the two modes of movement of said lever for indicating the frequency of the current generated, and means associated with said lever to actuate said Switches, controllers and indicating means.

9. An oscillation generator comprising an electric dischargev device and an oscillatory circuit including inductance and capacities, and an attachment therefor comprlsing means to adjust the value of the inductance and one capacity stepwise and the' other capacity continuously in defi nite sequence.

10. An oscillation generator including an electric discharge-device and an oscillatory circuit4 having inductance and capacities, andv an attachment therefor comprising means to adjustthe value of the inductance and one capacity stepwise and the other `capacity over itscomplete range in a continuous manner, the first capacity adjustments alternatingwith the inductarnce steps,

and the other capacity adjustmentsI alternatiig 'withl the said iirst capacity adjustments.

11. AAn oscillation generator attachment comprising a control lever, a plurality of switches, a` plurality of controllers, and means for giving said lever two modes ot movement to operate said switches and con- `for giving said lever two modes of movement, means for actuating said switches and one controller 1n proper sequence by one mode of movement of the lever, and for actuating the other controller by the other movement of said lever, whereby a unitary control is efected.

13. An oscillation generator attachment `comprising a control lever, a plurality of switches, a plurality ofcontrollers, means for giving said lever two modes of movement, means for transmitting one mode oi movement of said lever to the switches and one controller to actuate them in a desired sequence, and means for operating the second controller by the other movement of said lever, whereby a 4unitary control is cifected.

14. An oscillation generator attachment comprising a control levery a plurality oi switches, a plurality of controllers, means for giving vsaid lever two modes of movement, means for operating one controller continuously and said switches intermittently in proper' sequence by one inode of movement of said lever, and means to actuate the other controller by the other movement of said leven.

15. An oscillation generator attachment comprising a control lever, a pivot for said lever, a plurality of switches, a plurality of controllers, means for rotating said lever thereby operating one controller continuously and said switches intermittently in desired sequence and for oscillating said lever about said pivot to actuate the other controller.

16. An oscillation` generator attachment comprising a control lever, a pivot for said lever, a plurality of switches, a plurality of controllers, means for rotating said lever to actuate the switches in a definite sequence and operate one of the controllers over a complete cycle alternately with the actuation of said switches and for oscillating said lever about said pivot to actuate thel other controller. 17. An oscillation generator attachment comprising a control lever, a plurality of' switches, a plurality of controllers, means for giving said lever two modes of movement to operate said switches and controllers in a desired sequence, and indicating means associated with said lever.

18. An oscillation generator attachment comprising a control lever, a plurality of switches, a plurality oit-controllers, means for giving said lever two modes of movement, means for actuating said switches and one controller in proper sequence by operating the lever according to one mode of movement and for actuating the other controller by tlpe other movement of said lever, whereby a unitary control is effected, and indicating means associated with said lever and 'controlled by the dual motion thereof. 19. An oscillation generator attachment comprising a control'levcr, a plurality -of switches, a plurality of controllers, Imeans for giving said lever twolmodes of 'movement,means for transmitting move'mentof lone-Inode ofsaidylever the switches and lcomprising a control lever, a plii'r'ality Vof switches, a plurality of control-le' gfmeans for giving saidjlever twomo'defs* ot movement, means for. o erating one ly in proper sequence by one mode of movement of said lever, means to actuate the other controllerby the other mode of movement of said lever, whereby a unitary control is effected, and means for indicating the adjustment effected'.

21. An oscillation generator attachment comprising a control lever, a pivot for said j lever, a plurality of switches, a plurality of controllers, means for rotating said lever thereby operating one controller continuously and said switches intermittently in desired sequence and for oscillating 'said leverI about said pivot to actuatethe other controllei, and means for indicating the frequency setting effected.

22. An oscillation generator v attachment comprising a control lever, apivot for said lever, a plurality of switches, a plurality of controllers, means for rotating said lever to actuate the switches inl a de nite sequence and operate one ofthe controllers over a complete cycle alternately with the actuation of said switches and for bodily rotating said lever about said pivot to actuate thev other controller, and indicating means 'associated with said lever.

23. The combination with anioscillation generator comprising an electric discharge .device and sin-oscillatory circuit,v a ,filter .associated with said generator, means to adjust the constants ofthe circuit and lter includin a plurality of switches and controllers, and-means to actuate said switches and controllers in a definite sequence.

24. The combination with an oscillation generator comprising an electric dischargel device and an Voscillatory circuit, a load circuit, a filter connected to said generator and said load circuit for transmittingoscill' lations from tlie generator to the load circuit', a plurality of switches and controllers for, the oscillatory circuit, a plurality of switches for the filter, and means for simultaneously actuating one switch of each' series and said controllers in definite sequence.

25. The combination with l an oscillation l u,o ntroller` I continuously and said switches intermittentdevice and an oscillatory circuit, a load circuit, a filter connected to said generator and said load circuit for transmitting oscil7 lations from the. generator tothe load circuit, means to adjust the constants of the oscillatory circuit and filter including a plurality of switches and controllers, afrequency indicator, and means to actuate said switches and controllers in a denite sequence and alsoL said indicator.

126. The combination of an oscillatory circuit including inductance and capacities, a control lever adapted to be given two modes of movement, in'eans to transmit one mode -of movement of said lever to vary one capacity continuously over a complete cycle, means to transmit the other motion of said lever to vary the other capacity stepwise over its complete range and the inductance stepwise over its complete range, the lever being moved alternately in the two modes.

27. The combination with an oscillatory circuit, of means for adjusting the constants of said circuit including a plurality of j switches and controllers, and means to actuatesaid switches and controllers in a definite sequence.

28. f The combination with an oscillatory circuit, of means for adjusting'the constants of said 'circuit including a plurality of switches and controllers, and a control lever for actuating said switches and controllers in a definite sequence.

# i 2 9. Thefcombination with an oscillation generator including` an electric discharge device and an oscillating frequency determining circuit of means for adjusting the constantsl of said circuit including aplurality of switches and controllers, and a control lever adapted to be given two modes ',of movement to operate said switches and controllers in a desired sequence.

A 30. The combination with an oscillation generator comprising a source of current, an oscillatory circuit, meaps for adjusting the constants of said circuit, means to indicate the frequency Aof the current produced by' said generator, a load circuit, a filter for connecting said generator to said load cir@ cuit for transmitting current from the `generatorto `the load circuit, means for adjusting the constants of said filter, and a control lever adapted tobe given two modes of movementto operatesaid circuit and .filter adjusting `means in desired sequence and to indicate the frequency of'the oscilla-- tions produced by said generator) loo In' witness whereof, I hereunto subscribel my name this 20th day of June, A. D. 1921.v generator comprising an electric discharge HENRY C. HARRISON. 

